Which statement explains whether or not a person should use an experiment of a ball rolling down a hill as evidence that the force of gravity pulls objects straight down? A. They should not use it. The experiment has several dimensions of motion, including one parallel to the ground, so the motion of the ball does not directly test the force of gravity. B, They should not use it. The experiment has several dimensions of motion, including one parallel to the ground, so the motion of the ball does not directly test the force of gravity. C. They should not use it. Gravity should be tested in space, and this experiment could only be tested on Earth. D. They should not use it. Gravity should be tested in space, and this experiment could only be tested on Earth. They should use it. The experiment shows the ball falls toward the bottom of the hill, so it provides direct evidence that gravity pulls an object downward. E. They should use it. The experiment shows the ball falls toward the bottom of the hill, so it provides direct evidence that gravity pulls an object downward. F. They should use it. Any experiment on Earth involving natural motion will provide direct evidence that gravity pulls objects straight down.